Mesh Deformation due to rigging
What's apparent in your image is deformation that differs between the talon and the toe.  The reason for this is that the margin of the talon has different weights than the margin of the toe.  If the vertices have the same weights, they will move together.
This is probably due to using automatic weights on a mesh with non-manifold boundaries-- ie, multiple separated meshes.  Autoweights are not a great way to weight these kinds of meshes.  You can merge the seams and then re-weight, or you can weight by hand, or you can create a manifold &quot;cage&quot; mesh, autoweight that, and then copy weights from it to your non-manifold meshes.
If your problem is that the rig isn't in its rest pose even when all bones have no transforms-- that as soon as you weight a model, it moves at all, even correctly-- then the issue is due to constraints or drivers that you've put on bones in your rig that cause them to transform, even when the bones haven't been transformed in pose mode.